A semi-trailer truck crashed into a passenger train in the southern Australian state of Victoria on Tuesday, killing at least eight people and seriously injuring 12, police said.

Another 40 passengers suffered minor injuries in the collision at a level railroad crossing north of the rural town of Kerang in northwest Victoria, a police spokeswoman told Reuters.

"I am sad to say we now have eight confirmed fatalities," said police inspector Steve Gibson. "I understand they are still searching the wreckage for missing people," he told Sky television.

One passenger said the truck hit the second carriage, virtually cutting the train in half.

"The truck just didn't stop. He may have had the sun in his eyes. He tried to divert and he went off into the dirt and hit the carriage behind me," Sue Fyffee told Sky television.

"If the third carriage had not come off I think the whole train would have derailed," said a crying Fyffee.

"The back carriage is about 150 meters (450 feet) down the track and the carriage behind mine is just half gone. There is a big gapping hole in the side... the carriage is mangled, you wonder how anybody got out," she said.

Fyffee said passengers initially feared the train would be engulfed in fire. "People were screaming. There was glass everywhere. I helped the elderly who had broken bones," she said.

Emergency officials said many of the injured were being treated and assessed at the scene of the crash.

"We have air ambulances flying in and out," said Robert Jarman, chief of nearby Kerang Hospital.